In addition, the Met has announced they have charged Omar Ali with two offences under the Explosive Substance Act 1883 which relate to activity in Afghanistan.

The charges say he was in possession of or had under his control a quantity of explosive substances in 2012.

27 April 2017: Police secure a cordon near the scene on Whitehall near the Houses of Parliament in central LondonJustin Tallis/AFP

He will appear at Westminster Magistrates' Court on Wednesday (10 May).

Deputy Assistant Commissioner Neil Basu, senior national co-ordinator for counterterrorism policing, said at the time of the arrest: "Given the horrors in London of a few short weeks ago I wanted to reassure the public that our increased activity to combat terrorism over the last two years continues, both by police and security services.

"Activity continues around the clock to identify and stop these threats and we are making arrests on a near daily basis.

"I would like to reassure everyone that across the country officers are working round the clock to identify those people who intend to commit acts of terror."

27 April 2017: The arrest in Whitehall near the Houses of Parliament in central LondonNiklas Halle'n/AFP